Open the 
Dispatch Board
window.
Browse to the relevant service order. Click Planning, Resource Allocations.
Select the entry with the service task to which you want to allocate a resource, and then click Planning, Res. Group Availability.
In the Res. Group Availability (Service) window, select a resource group you want to allocate.
Select a date on which the resource group has enough available hours for the task and which is close to the response date of the service order.
In the Quantity to Allocate field, enter the number of hours you want to allocate the resource to the service task for.
Click Allocate to allocate the selected resource group on the selected date. The program automatically returns to the Resource Allocations window.
The program automatically selects the Active option in the Status field.